疣粒野生稻抗白叶枯病新基因的初步鉴定

以10个菲律宾白叶枯病菌小种和1个中国白叶枯病菌小种为供试菌系，以高感白叶枯病水稻品种IR24及携有不同抗白叶枯病基因的近等基因系IRBB1等16个材料作为参照，对粳稻品种8411/疣粒野生稻体细胞杂交获得的两个抗白叶枯病新种质SH5和SH76进行了白叶枯病抗谱鉴定。结果表明SH5和SH76在苗期的抗谱较广，并且与已知抗病基因的抗谱不同，但与IRBB5(xa5)和IRBB7(Xa7)相似。分别用xa5和Xa7的分子标记2F_1R和M5进行检测，确定SH5和SH76中不含有xa5和Xa7基因。初步推测SH5、SH76可能含有一个新的抗病基因或者一个连锁的基因簇群。

Primary Identification of a New Resistance Gene to Bacterial Blight from Oryza meyeriana

Two new germplasms, SH5 and SH76, were acquired through somatic hybridization with the wild rice species Oryza meyeriana L. as the donor parent, which was resistant to bacterial blight (BB). The BB resistance spectra of SH5, SH76 and other 16 reference lines carrying different major BB resistance genes were evaluated and compared using 11 BB races collected from the Philippines and China. The results showed that SH5 and SH76 had a broad resistance spectrum at the seedling stage, which was different from those of the other resistance genes identified, but similar to the lines IRBB5 (carrying xa5) and IRBB7 (carrying Xa7). The molecular markers 2F_1R and M5, closely linked to xa5 and Xa7, respectively, were used to detect whether the two genes existed in SH5 and SH76, and it was found that there was no xa5 and Xa7 in SH5 and SH76. It was deduced that a new gene, or a linked gene cluster might exist in SH5 and SH76.